Apparatus for purifying lubricating oil



Oct. 18, 1938.

J. R. MILLER 2,133,359

APPARATUS FOR PURIFYING LUBRICATING OIL Filed NOV. 1, 1935 WITNESSES INVENTOR BY fl/iaaw.

Patented Oct. 18, 1938 UNITED STATES PATENT OFFICE James Boys Miller, Pittsburgh, Pa. Application November 1, 1935, Serial No. 47,897

Claims.

This invention relates to an apparatus for purifying used lubricating oil, and more particularly to the rectification of lubricating oil during use in internal combustion engines.

It is common knowledge that the crank cases of internal combustion engines, especially in automotive vehicles, should be drained of their lubricating oil at intervals and refilled with new oil to assure proper engine lubrication, to reduce engine wear and power loss, and to prevent burning out of bearings and the scoring of pistons and cylinder walls. Various factors contribute to the depreciation of the lubricant and consequently to the possibility of the enginebeing injured in *the manner just referred to. A major one is probably contamination of the oil by volatile agents such as water and gasoline. Thus, moisture in the atmosphere and in the products of combustion condenses on the cold Walls of the crank case and cylinders; it emulsifies with the 011 thus reducing its lubricating efiiciency and in some instances causing it to carry in suspension a greater amount of foreign abrasive material than it would normally. Because of the slow movement of the emulsified oil the sludge which it carries has a greater tendency to clog oil ducts in the bearings. Furthermore, water may be forced out of the emulsion in the bearings to form a water seal that may stop the flow of 011 to the bearings.

Another of the factors referred to is the condensation on the cylinder walls of the light nonlubricating oils from the saturated oily vapors in the crank case. These light non-lubricating oils are due to dilution of the crank case oil by gasoline escaping past the pistons, and by excessive choking. The condensate thus formed on the cylinder walls during the up stroke of the pistons destroys or dilutes the oil film thereon, which causes wear and loss of power and permits the gasoline vapor above the piston to blow past the piston into the crank case where it further dilutes the oil.

Also, chemical elements in the gasoline or products of combustion may combine with water in the crank case to form acids that cause corrosion. The volatile agents thus present in the oil contribute to a large extent to the formation of sludge which, because of its tarry nature, retards the flow of oil and clogs the oil ducts.

Finally, particles of grit and dirt always find their way into the oil from the outside air or from metal abrasion, while particles of free carbon formed in combustion likewise get into the oil.

" The crank cases of most modern automotive vehicles are ventilated in such a manner as to permit a large volume of air to pass through them intended to carry away the volatile agents given off by the oil heated therein. This large volume of air carries with it into the crank case a con- 5 siderable amount of dust and the like, and likewise increases condensation by cooling the engine. These various types of grit act as abrasives that contribute to wear in the engine.

It is among the objects of this-invention to provide an apparatus for purifying oil in internal combustion engines which make it unnecessary frequently to drain crank cases and refill them with new oil, permit the use of light and inexpensive oils, improve engine lubrication and mal5 terially reduce engine wear, conserve power, lower operating costs and increase the mileage obtained from a given amount of fuel, minimize the effect of atmospheric temperatures on the starting and operation of engines, facilitate starting, and which in themselves are simple, inexpensive, dependable and highly efficient.

In accordance with this invention lubricating oil is pumped from a crank case and spread out in a film at a temperature high enough to cause volatile products to be driven off from the film, and the vaporized volatile materials are then carried away by an induced current of air. The devolatilized oil then passes through a sludge trap where the sludge settles out. Preferably the oil also passes through a filter where particles of grit and carbon are filtered out. The volatile substances given off by the film of oil are preferably carried, by a small current of air introduced through the crank case, into the intake manifold from which they pass to the cylinders where they serve as fuel and a top lubricant.

The preferred embodiment of the invention is illustrated in the accompanying drawing, in which Fig. 1 is a side elevation of a combined rectifier 4,0 and sludge trap; Fig. 2 is a vertical section therethrough; Fig. 3 is a plan view of the rectifier; Fig. 4 is a plan View taken on the line IV-IV of Fig. 2; and Fig. 5 is a side view, partly in section, of an oil filter.

Referring to the first three figures of the drawing, a cylindrical metal casing I has an inlet port 2 in one side, an outlet port 3 in the side wall diametrically opposite, and a drain opening 4 in its bottom wall. Disposed in this casing is a 5 metal cup 6 (Fig. 2) having an opening I in its bottom registering with the drain in the casing at which point the two are tightly connected together by a suitable tubular fitting 8. The top of the cup is provided with a radial flange 9 terminating in an upwardly extending peripheral flange H that engages the cylindrical wall of the receptacle. Resting on radial flange 9 is a circular plate l2 provided near its periphery with a plurality of openings l3 into the cup. The top of casing i is closed by a cover I4 having a recessed peripheral flange l6 that clamps the peripheral flange of the cup into sealing engagement with the wall of the casing, thereby sealing the top of the casing and forming an oil rectifier.

The casing cover is provided in its center with a port I! through which lubricating oil tobe purified is supplied from an internal combustion engine. Conduit I 8, through which oil is supplied to the rectifier, may be connected to the oil pump or oil gauge line or to any other suitable point from which oil can be pumped from the crank case by its oil-circulating pump. It is a feature of this invention that oil enters the casing-through port I! and strikes the center of plate l2 slowly enough to permit it to spread out in a thin film over the plate. A desirable rate of fiow has been found to be that which permits a quantity of oil equal to the oil capacity of the crank case to pass through the rectifier in one hour when the vehicle is traveling at 30 miles per hour. This very slow rate of flow may be obtained without danger of clogging the supply conduit by inserting a. nipple l9 between conduit 18 and port l1, the nipple having an internal seat 2| on which a ball 22 is loosely disposed. By scratching the ball-engaging surface of this seat with a file, very small oil grooves are formed, the number and depth of which determine the rate of flow of oil past the ball. Normal vibration of the ball on its seat when the engine is running prevents foreign matter from lodging between the ball and seat in the small grooves and clogging the supply line.

To assure the oil spreading out uniformly in all directions on the plate, especially when the vehicle is not horizontal, so that the film will be as thin and have as great .an area as possible, the upper surface of the plate is provided with a plurality of bosses 23 (Figs. 2 and 3) which break up the flow of oil in any one direction and cause it to spread out in all directions over the plate. As the oil reaches perforations l3 near the edge of the plate it flows through and down the side of the cup which is preferably provided with annular corrugations 24 that strengthen the cup and increase its surface area.

To drive volatile matter out of the oil it is heated to an appropriate temperature, usually about 400 F., after it leaves the crank case. Although the oil can thus be heated on its way to the rectifier, it is preferred to effect the heating of the oil as it flows in a film across the plate and down the inside of the cup, by bleeding exhaust gases from the engine into casing I through its inlet port 2, the gases escaping through outlet port 3 after circulating around the outside of cup 6 which is heated thereby. Due to the fact that the oil is spread out in a thin film in the rectifier its surface tension is reduced so that volatile substances may escape from it more freely, and it is quickly brought to a high temperature to release those substances.

In some cases, such as in trucks in which the engines heat more than in ordinary automobiles, it may be desirable to connect a thermostat 26 in outlet 3 of the casing l, as shown in Fig. 2. The bi-metallic valve 2! reduces the size of the thermostat outlet when the temperature in the casing approaches a point where it might crack the oil, and thereby reduces the fiow of exhaust gases through the casing.

The volatile matter given oif by the film 01' oil on the sides of the cup passes upwardly into cover l4 through perforations l3 in the plate and through perforations 3| in the tops of bosses 23. The vapors, together with those given off by the oil film on the plate, are then carried away by a current of air passing over the plate. This air is introduced into the top of the rectifier through a port 32 in the cover, and preferably is supplied from the front end of the crank case in the rear end of which a small opening is provided to permit the air to first circulate through the crank case and pick up whatever volatiles there may be in it. This current of air, laden with vapors evolved from the oil in the heated crank case, passes between plate l2 and cover M where it picks up the vapors given off by the oil in the rectifier and carries them out through an outlet port 33 in the cover to the intake manifold between the carburetor and the cylinders of the engine. The consumable volatile matter then serves as fuel for the engine while the oily vapor lubricates the upper walls of the cylinders. In this way better lubrication is obtained and more mileage is secured. The suction in the intake manifold draws the air from the crank case.

It has been found that a tube of one-eighth inch outside diameter will usually exhaust sufficient .air from the rectifier to carry away the volatile matter therein. Consequently, only a very small current of air need pass through the crank case, whereby the introduction into the crank case of road dust and grit is materially reduced, and the engine walls are not cooled by the air sufficiently to increase condensation of water vapor thereon.

' The oil in the rectifier flows down the sides of the cup and out through tubular fitting 8 the lower end of which opens into the top of a sludge trap 35. This trap comprises a receptacle 3'! sealed at its lower end by a bottom plate 38 on which a bowl 39 (Fig. 2) is rigidly mounted by means of a fitting 4| extending through registering openings in the plate and bottom of the bowl and receiving a threaded drain plug 42. The bowl is spaced from the top and side walls of the receptacle, and is covered by a fiat plate 43 having a depending peripheral flange 44 telescoping over the top of the bowl. This plate is also provided with a plurality of openings 46 therethrough, such as round holes and arcuate slots as shown in Fig. 4.

Oil entering the receptacle from the rectifier above strikes plate 43 and spreads out over it in a thin film, and as soon as this oil reaches openings 46 it passes through them into the bowl until the latter is filled. After that the film of oil flows outwardly across plate openings 46 through which it can not pass because the bowl is full of oil. However, sludge in the oil settles out of the film as it fiows over the openings in the plate, and the sludge sinks to the bottom of the bowl. The film of desludged oil flows down the outside of the bowl, where it is cooled somewhat, and out of the receptacle through an outlet port 41 near its lower end from which the oil is returned to the crank case. At intervals the sludge thus collected in the bowl is drained out by removing drain plug 42 in the bottom of the trap.

However, as some grit and other solid foreign matter may not be removed from the oil as it passes through the sludge trap, a filter is provided for filtering such matter out of the oil. As shown in Fig. 5, a cylindrical filter casing is provided with a removable cover 52 directly below which there is an inlet port 53 through the side wall of the casing. The central portion of the bottom wall of the casing is tapered, downwardly to form a sump in the center of which is an outlet port 54. Remo-vably disposed in the filter casing below the inlet port is a filter block 56 through which oil must pass in passing through the casing.

- In oil filters now in use in which fibrous filtering media are used, the oil soon packs the filter medium into a hard block that is ineffective as an adequate filter, and may even prevent oil from flowing through it. To obviate this difficulty the filter medium provided by this invention is composed of cotton or other suitable fibrous material the major portion of which is prevented from packing solidly together by resilient material 51,

such as kapok and curled threads or shavings of copper or other metal, intermingled with the cotton fibers. Consequently, the life of the filter block is materially lengthened, and its efficiency is greatly improved. The lower portion of the block is preferably free of any such resilient material so that it will be denser than the remainder of the block.

The filter block is supported by a rigid perforated metal plate 58 seated on the bottom of the casing above the sump. Resting on this plate is a fine mesh strainer screen 59 of copper or the like for filtering out any particles that may pass through the filter block. To prevent the cotton fibers of the filter block from clogging the screen, a second perforated metal plate BI is disposed on the screen for spacing the filter block therefrom. Resting on top of the filter block is a rigid perforated metal plate 62 which is pressed downwardly, to keep the cotton fibers massed together, by a coil spring 63 compressed between it and cover 52. Screen 59 and plate 6|, as well as plate 58 if desired, may be, and preferably are, removably associated with the casing so that they can be removed if need be, for cleaning for example.

Oil passing downwardly through the filter block and the three perforated metal plates and the strainer screen enters the sump in the bottom of the casing. A nipple 54, closed at its upper end, is tightly mounted in outlet port 54 and is provided in its side walls with openings 66 through which the filtered oil in the sump escapes from the casing. Port 54 may be connected by a suitable conduit to inlet port I! of the rectifier, or the conduit may lead directly back to the crank case.

An apparatus for purifying lubricating oil constructed in accordance with this invention, makes it unnecessary to change the oil in internal combustion engines at frequent intervals. The oil is maintained dehydrated so that the evils attendant on diluted and emulsified oil are not present, and the formation of sludge which clogs oil ducts and generally interferes with proper lubrication is materially reduced While that which is formed is quickly removed from the oil. This makes it possible to use lighter grade oils that give better lubrication in modern engines, and cheaper oils that reduce the operating costs of such engines. Furthermore, the introduction of abrasive matter through the crank case is greatly reduced, whilethat which finds its way into the oil is effectively removed by the longlived filter.

. filterable particles remaining in The rectifier, sludge trap and filter also cooperate in purifying the used oil in that the emulsion of oil and water which restrains minute and filterable particles of grit carried therein from agglomerating is destroyed in passing through the rectifier, and other foreign agents in the oil which may resist agglomerating of those particles after the water has been driven off from the oil are removed by the sludge trap, whereby the the oil are allowed to mass together into larger particles which are removed from the oil as it flows through the filter. In addition to the function described, the sludge trap acts also as a cooler for the treated oil. As will be observed, the oil is heated to a temperature substantially above that normally attained by the oil in the crank case, and it would not be desirable to return such heated oil to the crank case. However, the oil is cooled sufiiciently in the sludge trap that it may be returned directly to the crank case.

The invention has been described with reference to one embodiment, by way of example. Many modifications are permissible which lie, however, within the contemplation and scope of the invention. Thus, bowl 6 could be heated electrically, as by a resistance heating coil appropriately disposed exteriorly of the bowl. Also, thermostat 26 may be connected to inlet port 2 instead of to outlet port 3 as shown. Other permissible changes will appear to those skilled in the art.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention, and have illustrated and described what I now consider to be its best embodiment. However, I desire to have it understood that, Within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In apparatus for purifying lubricating oil, a plate, a conduit for supplying oil to the plate, and a flow-restricting element connected to said conduit, said element comprising a tubular member provided interiorly with an annular seat facing the direction from which said oil flows to the plate, a ball loosely mounted on said seat and urged toward it by the oil fiowing through said conduit, the ball-engaging surface of said seat being provided with at least one groove serving as an oil passage past the ball and means for heating said plate to drive volatile matter out of the oil thereon.

2. In apparatus for purifying lubricating oil, a cup provided with an oil outlet, a plate disposed above the cup, means for supplying oil to the plate at a rate to cause it to spread out in a film thereon, said plate being perforated adjacent its edge to allow said film of oil to pass into said cup and being provided on its upper surface with a plurality of perforated bosses for causing the oil to spread out substantially uniformly in all directions on the plate, means for heating said cup to drive volatile matter out of said oil on the plate and the sides of the cup, the volatile matter freed in the cup rising out of it through said perforations, and means for passing a current of air above said plate to carry away said volatile matter.

3. In apparatus for purifying lubricating oil, a cup provided with an oil outlet, a plate disposed above the cup, a conduit for supplying oil to the plate, an annular seat in said conduit facing the direction from which said oil fiows to the plate, a ball loosely mounted on said seat and urged toward it by the oil flowing through the conduit, the ball-engaging surface of said seat being provided with a groove serving as an oil passage past the ball, said plate being provided with perforations to allow oil to pass from it into said cup, and means for heating said cup to drive volatile matter out of said oil.

4. In apparatus for purifying lubricating oil, a cup provided with an oil outlet, the side wall of the cup being provided interiorly with a plurality of substantially horizontal vertically spaced independent annular corrugations, a plate disposed above the cup, means for supplying oil to the plate at a rate to cause it to spread out in a film thereon, said plate being perforated adjacent its edge to allow said film of oil to pass into said cup and fiow down and cascade over said corrugations from one to the other, a cover for said cup having its top spaced from said plate, means for heating said cup to drive volatile matter out of said film and up into said cover, and means for passing a current of air through said cover to carry away said volatile matter.

5. In apparatus for purifying lubricating oil, a cup provided with an oil outlet, a plate disposed across the top of the cup, means for supplying oil to the plate at a rate to cause it to spread out in a film thereon, there being space at the edge of the plate between it and said cup to allow said film of oil to pass into the cup, the upper surface of the plate being provided with a plurality of bosses for causing the oil to spread out substantially uniformly in all directions on the plate, means for heating said cup to drive volatile matter out of said oil on the plate and the sides of the cup, and means for passing a current of air above said plate to carry away said volatile matter.

JAMES ROYS MILLER. 

